Method and apparatus for determining the transmission data rate in a multi-user communication system

Abstract

A method and apparatus are described for controlling the data rates for communications to and from a base station and a plurality of remote users. The usage of the communications resource whether the forward link resource (from base station to remote users) or reverse link resource (from remote users to base station) is measured. The measured usage value is compared against at least one predetermined threshold value and the data rates of communications or a subset of communications on said communications resource is modified in accordance with said comparisons.

1. A method of controlling a vocoder encoding rate for speech transmitted to a remote unit on a wireless channel, comprising:
 obtaining a usage value indicating an amount of the wireless channel that is in use based on how many users are accessing the wireless channel and a data rate transmitted by each user; 
 comparing the usage value with a channel usage threshold; and 
 selecting a vocoder encoding rate based at least in part on a result of the comparing. 
 
     
     
       2. The method of  claim 1 , wherein the selecting comprises selecting a vocoder encoding rate from among a plurality of supportable vocoder encoding rates. 
     
     
       3. The method of  claim 1 , wherein the usage value is compared with a lower channel usage threshold value and an upper channel usage threshold value. 
     
     
       4. The method of  claim 3 , wherein the selecting comprises selecting a vocoder encoding rate based on at least one result of the comparing. 
     
     
       5. The method of  claim 1 , wherein the obtaining comprises receiving a rate control signal from the remote unit that indicates whether a maximum data rate should be increased or decreased. 
     
     
       6. The method of  claim 5 , wherein the rate control signal includes a measure of frame error rate for signals received by the remote unit. 
     
     
       7. A base station configured to control a vocoder encoding rate for speech transmitted to a remote station on a wireless channel, comprising:
 means for obtaining a usage value indicating an amount of the wireless channel that is in use based on how many users are accessing the wireless channel and a data rate transmitted by each user; 
 means for comparing the usage value with a channel usage threshold; and 
 means for selecting a vocoder encoding rate based at least in part on a result of the comparing. 
 
     
     
       8. The base station of  claim 7 , wherein the means for selecting comprises means for selecting a vocoder encoding rate from among a plurality of supportable vocoder encoding rates. 
     
     
       9. The base station of  claim 7 , wherein the usage value is compared with a lower channel usage threshold value and an upper channel usage threshold value. 
     
     
       10. The base station of  claim 9 , wherein the means for selecting comprises means for selecting a vocoder encoding rate based on at least one result generated by the means for comparing. 
     
     
       11. The base station of  claim 7 , wherein the means for obtaining comprises means for receiving a signal from the remote station. 
     
     
       12. The base station of  claim 11 , wherein the signal includes a measure of frame error rate for signals received by the remote station. 
     
     
       13. A base station configured to control a vocoder encoding rate for speech transmitted to a remote station on a wireless channel, comprising:
 an energy computation module configured to obtain a usage value indicating an amount of the wireless channel that is in use based on how many users are accessing the wireless channel and a data rate transmitted by each user; and 
 rate control logic coupled to the energy computation module and configured to compare the usage value with a channel usage threshold and to select a vocoder encoding rate based at least in part on a result of the comparing. 
 
     
     
       14. The base station of  claim 13 , wherein the rate control logic is configured to select a vocoder encoding rate from among a plurality of supportable vocoder encoding rates. 
     
     
       15. The base station of  claim 13 , wherein the usage value is compared with a lower channel usage threshold value and an upper channel usage threshold value. 
     
     
       16. The base station of  claim 15 , wherein the rate control logic is configured to select a vocoder encoding rate based on at least one result of the comparison. 
     
     
       17. The base station of  claim 13 , further comprising a receiver coupled to the energy computation module and configured to receive a signal from the remote station. 
     
     
       18. The base station of  claim 17 , wherein the signal includes a measure of frame error rate for signals received by the remote station. 
     
     
       19. A processor for controlling a vocoder encoding rate for speech transmitted to a remote unit on a wireless channel, the processor being configured to:
 obtain a usage value indicating an amount of the wireless channel that is in use based on how many users are accessing the wireless channel and a data rate transmitted by each user; 
 compare the usage value with a channel usage threshold; and 
 select a vocoder encoding rate based at least in part on a result of the comparing.